Field of the Invention
The invention relates to a circuit configuration for generating an interrupt signal for a microprocessor.
As is known, microprocessors and microcontrollers have input terminals for signals characterizing the operating state of the circuit environment, with the result that an interrupt signal that indicates an interrupt state can be generated internally. The microprocessor thereupon interrupts the currently running program and processes a subroutine that reacts to the state triggering the activation of the interrupt signal. Such a circuit is described in German Utility Model G 94 03 121.5 U1.
When controlling complex switching functions, for example in cyclically operated light modules, converters, or in the clocked regulation of electric motors, it is necessary to monitor a multiplicity of individual state signals and operating states formed from a combination of state signals in order to act on the current operation of the configuration by a suitable control by the microcontroller. Conventional microprocessors having individual state input signals that are processed independently of one another are overtaxed in this situation.
Although it is possible to monitor a plurality of state input signals by software-controlled, cyclic interrogation, so-called poling, this requires a considerable computation complexity given a relatively high number of state input signals to be monitored, and it does not ensure reliable identification of operating states which are present only momentarily and are supposed to trigger an interrupt.
In the German Utility Model G 94 03 121.5 U1, a plurality of interrupt signals are connected via a programmable distributor to the interrupt signal input of the microprocessor.
The generation of an interrupt signal by a comparator configuration that ascertains the change in state of the signals on a data bus is described in German Patent DE 26 54 247 B1.